1. Field of the Invention
The present invention relates to an electrical connector, especially to an LGA socket connector for connecting a CPU chip and a printed circuit board.
2. Background of the Invention
Various types of conventional electrical connectors are known for electrically connecting an IC package, such as a CPU, with a circuit board, such as a printed circuit board (PCB).
One of the widely-known electrical connectors is a land grid array (LGA) socket connector, particularly utilized for electrically connecting the CPU with the PCB. Typically, the LGA socket connector includes an insulative housing with a plurality of terminals assembled therein, a stiffener generally defining an opening to grasp a periphery of the housing, a clip and a lever respectively disposed adjacent two ends of the housing to jointly press the CPU chip onto the housing so as to make electrically connection between the CPU chip and the LGA socket.
In general, the housing, the stiffener, the clip each have a symmetrical configuration except for the lever. More specifically, the level, generally formed of a heavy metal, is composed of a locking portion and a driving portion linked to the locking portion. When the LGA socket is in a horizontally locked position, the driving portion is positioned beside one side of the clip, while the locking portion of the lever is disposed adjacent one end of the housing and in opposed relationship with the clip. As such, a center of gravity of the connector tends to be at a position biased towards the driving portion of the lever, thereby causing positional misalignment between a geometry center of the connector and the center of gravity of the connector.
When the LGA socket is horizontally locked and placed on the printed circuit board, the LGA socket becomes inclined with respect to the circuit board due to such positional misalignment between the geometry center and the gravity center of the connector. Coplanarity of the solder balls on the connector along a mounting interface is thus influenced by potential variations in sizes of respective solder balls, when the inclined connector is attached to the printed circuit board by solder balls melt at a high temperature. This will often result in electrical connection failure at a certain area between the inclined connector and the printed circuit board.
In view of the above, it is strongly desired to provide a new LGA socket connector, which overcomes the above-mentioned disadvantages.